Foley identified most of the weapons through photographs. But a prosecutor handed Foley seven machine guns -- one by one -- and asked him to identify them for the jury.

Another retired state police officer also testified Thursday, identifying Bulger in 1980 video surveillance meeting with members of his Winter Hill Gang and members of the rival Italian Mafia.

During opening statements Wednesday, Assistant U.S. Attorney Brian Kelly described Bulger, now 83, as a "hands-on killer" who was responsible for "murder and mayhem" in Boston for almost 30 years.

One of the nation's most wanted fugitives when he fled Boston in 1994, Bulger finally was captured in 2011 in Santa Monica, Calif., where he had been living with his longtime girlfriend.

Bulger's lawyer, J.W. Carney Jr., acknowledged that Bulger made millions through drugs, illegal gambling and loan-sharking, but told the jury that three ex-mobsters who have pinned murders on Bulger cannot be believed. Each of the men received "extraordinary" deals from prosecutors in exchange for their cooperation, Carney said.

The defense also denied prosecution claims that Bulger was an FBI informant and provided information on the rival New England Mafia.

Carney attacked the credibility of three once-loyal Bulger cohorts who are expected to be the prosecution's star witnesses: convicted hit man John Martorano, former Bulger partner Stephen "The Rifleman" Flemmi and former Bulger lieutenant Kevin Weeks.

Carney said Martorano, who served 12 years in prison after admitting to killing 20 people, was able to dictate the terms of his deal with prosecutors.

"The federal government was so desperate to have John Martorano testify ... they basically put their hands up in the air and said, 'Take anything you want,'" Carney said.

Kelly told jurors that Bulger headed the violent Winter Hill Gang that "ran amok" in Boston for three decades, killing 19 people, extorting millions of dollars from drug dealers and other criminals, and corrupting police and FBI agents.

"At the center of all this murder and mayhem is one man -- the defendant in this case, James Bulger," Kelly said.

Carney insisted that Bulger was not an FBI informant. He said his client paid FBI agents to tip him off when he and his gang were being investigated or about to be indicted.

"James Bulger never, ever -- the evidence will show -- was an informant," Carney said.

Kelly said Bulger's gang succeeded by instilling fear in other criminals and corrupting law enforcement officials.

"It was part of a strategy they had, and it worked for them," Kelly said.

Kelly slowly read the names of each of the 19 victims while showing their pictures to the jury as relatives of the victims watched from the courtroom.

Rare photos of Whitey Bulger from 1980s

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Surveillance photos taken from inside a garage in 1980 give a rare look inside the life of James Whitey Bulger.